Study on the Structure of Supramolecular Inclusion Complex of β-Cyclodextrin with Retinoic Acid

Inclusion compound of retinoic acid with (-cyclodextrin was prepared by coprecipitating method, the structure of resulting product was studied by elemental analysis, differential scanning caloriemetry(DSC) analysis, FT-IR spectroscopy and X-ray diffractometry, and the formed supramolecule self-assembles in aqueous solution according to molar ratio 2:1 of host-guest.

Development and evaluation of vinpocetine inclusion complex for brain targeting

The objective of this paper is to prepare vinpocetine(VIN)inclusion complex and evaluate its brain targeting effect after intranasal administration.In the present study,VIN inclusion complex was prepared in order to increase its solubility.Stability constant(Kc)was used for host selection.Factors influencing properties of the inclusion complex was investigated.Formation of the inclusion complex was identified by solubility study and DSC analysis.The brain targeting effect of the complex after intranasal administration was studied in rats.It was demonstrated that properties of the inclusion complex was mainly influenced by cyclodextrin type,organic acids type,system pH and host/guest molar ratio.Multiple component complexes can be formed by the addition of citric acid,with solubility improved for more than 23 times.Furthermore,In vivo study revealed that after intranasal administration,the absolute bioavailability of vinpocetine inclusion complex was 88%.Compared with intravenous injection,significant brain targeting effect was achieved after intranasal delivery,with brain targeting index 1.67.In conclusion,by intranasal administration of VIN inclusion complex,a fast onset of action and good brain targeting effect can be achieved.Intranasal route is a promising approach for the treatment of CNS diseases.

Formation of the Inclusion Complex of Orange Ⅱ with β-Cyclodextrin and Its Photostability

Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange Ⅱ is 1∶1. The formation constant K=1.236×10 3 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constant K=1.266×10 3 L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange Ⅱ solutions containing β-CD and TiO_ 2 was smaller by 51.9% than that of the Orange Ⅱ solutions only containing TiO_ 2 , while in the case of direct photolysis of Orange Ⅱ solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange Ⅱ under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis.

FORMATION OF THE CRYSTALLINE INCLUSION COMPLEX BETWEEN β-CYCLODEXTRIN AND POLYPROPYLENE

PP can be included in the cavities of cyclodextrin (CD). The crystalline inclusion complex between β-CD and lowmolecular weight polypropylene (PP) was obtained and investigated. α-CD and γ-CD did not form crystalline inclusioncomplexes with PP. The FTIR spectra, TGA, X-ray diffraction spectra were studied, ~1H-NMR spectra and ^(13)C CP/MAS NMR spectra were used to characterize the crystalline inclusion complexes.

Inclusion Complex of Paclitaxel in Hydroxypropyl-β-cyclodextrin

Introduction Paclitaxel （as Taxol） is a kind of diterpenoid natural product extracted from Chinese yew. It has been reported to have high anti-tumor effects, such as the activity against oophorama, mammary cancer, encephaloma, cervical carcinoma, and non- small-cell lung carcinoma. One of the major problems of paclitaxel applied to therapy is its extremely low solubility in water. In addition, paclitaxel is administered as a slow infusion in a vehicle consisting of Cremophor EL （ polyoxyethylated castor oil ）. However, Cremophor has been observed to cause severe, occasionally fatal hypersensitivity reactions in animals and humans. Therefore, paclitaxel therapy includes a prophylactic regimen of antihistamines and corticosteroids , along with a prolonged infusion time to reduce the severity and incidence of hypersensitivity reactions. Because of the reasons mentioned above, currently its preparation needs to be improved further.

Crystal and Molecular Structure of an Inclusion Complex of p-tert-Butylcalix[6]arene with Toluene

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Synthesis of a Novel Aromatic Diamino-bridged Bis(β-cyclodextrin) and its Inclusion Complexation with Dyes Molecules

A novel brideed bis（β-cvclodextrin）, 4, 4＇-diaminodiphenyl ether-bfiged-bis （6-aimino-6-deoxv-β-cyclodextrin） 3, has been synthesized and its inclusion complexation behavior with three linear＇guest dyes （AR, NR and MB ） has been investigated by. means of fluorescence spectrometry. The-result obtained demonstrated that the novel bridged bis（β-cyclodextnn） showed much higher affinities towards guest dyes than native β-cyclodextrin.

PREPARATION AND CHARACTERIZATION OF INCLUSION COMPLEXES OF TWO-ARM LINEAR AND FOUR-ARM STAR-SHAPED POLY(ε-CAPROLACTONE)S WITHα-CYCLODEXTRIN

Both four-ann star-shaped poly（ε-caprolactone） （4sPCL） and two-ann linear PCL （2LPCL） were synthesized and their inclusion complexation with α-cyclodextrin （α-CD） were studied. The inclusion complexes （ICs） formed between the PCL polymers and α-CD were characterized by ^1H-NMR, DSC, TGA, WAXD, and FT-1R, respectively. Both branch ann number and molecular weight of the PCL polymers have apparent effect on the stoichiometry （CL：CD, mol：mol） of these ICs. All these analytical results indicate that the branch arms of the PCL polymers are incorporated into the hydrophobic α-CD cavities and their original crystalline properties are completely suppressed. Moreover, the inclusion complexation between two-ann linear or four-ann star-shaped PCL polymers and α-CD not only enhances the thermal stability of the guest PCL polymers but also improves that of α-CD.

DSC and NMR Study on the Inclusion Complex of Lappaconitine with b-Cyclodextrin

The inclusion complex of lappaconitine (Lap) with b-cyclodextrin (b-CD) has been studied by the differential scanning calorimetry (DSC) and 1H-NMR, 2D-NMR spectroscopy. The structure of the complex has been deduced.

X-Ray Diffraction and NMR Study of Inclusion Complex of Podophyllotoxin with β-Cyclodextrin

The inclusion complex of podophyllotoxin (P) with β-cyclodextrin (β-CD) has been studied by X-ray diffractometry and 1HNMR、13CNMR spectroscopy. The complex structure is deduced.

Crystal Structure of a Novel Sandwich Inclusion Complex of β-Cyclodextrin with α-Naphthylacetic Acid

A supramolecular inclusion complex between β-cyclodextrin（β-CD） and α-naphthylacetic acid was prepared, and its crystal structure was investigated by single-crystal X-ray crystallography. The complex contains two β-CD molecules, one α-naphthylacetic acid, two ethanols and twenty-eight water molecules in the asymmetric unit, which could be formulated as [（C42H70O35）2·（C12H10O2）·（C2H5OH）2·28H2O]. Two β-CD molecules constitute a dimer by face-to-face contact of their secondary hydroxyl sides. At the interface of the dimer, one α-naphthylacetic acid molecule is sandwiched between two β-CD molecules. Each β-CD unit of the dimer includes one ethanol molecule in its cavity. The β-CD dimers are linked together via hydrogen bonding to form layers that are stacked in a brickwork-like pattern. The comparative study of some sandwich complexes elucidates that the interface of the β-CD dimer has a stronger inclusion capacity than the cavity of β-CD for some suitable planar guest molecules. The novel inclusion structure results from the competitive inclusion of α-naphthylacetic acid and ethanol.

Studies on the Stability and Structure of β-cyclodextrin Vitamin D_2 Inclusion Complex

The inclusion complex of β\|cyclodextrin (βCD) with Vitamin D 2 (VD 2 ) was prepared in 60% ethanol aqueous solution. The accelerated tests of the inclusion complex βCD\|VD 2 were performed under strong light, high temperature and high humidity. The results showed that the content of VD 2 in the inclusion complex was still kept 85%~95% after two years, while that in the βCD and VD 2 mixture was just 17%~22%. It indicated that VD 2 in inclusion complex was much more stable than pure VD 2. Therefore, adding the inclusion complex βCD\|VD 2 into “Longmu” Zhuanggu Chongji, a medicine for children to prevent and cure rickets, can not only decrease the expense of VD 2, but also enhance the stability of the products. IR, X\|ray, DTA and UV techniques were used to characterize the structures of the inclusion complex. The results indicated that intermolecular hydrogen bonds formed in the βCD\|VD 2 inclusion complex.

Studies on the Inclusion Complex Reaction and Fluorescent Analytical Application of β- cyclodextrin with Hymecromone

The inclusion complex reaction condition and the mechanism of β cyclodextrin with hymecromone have been studied by fluorescent spectrum. The fluorescent intensity and the stability of the system can be qreatly increased in qiven condition, and the formation constant of the inclusion complex reaction has been determined too. The system can be applied to the determination of trace amounts of hymecromone, the maximum fluorescent intensity is obtained with excitation and emission wavelength at 362 nm and 452 nm, respectively. The linear range for hymecromone is 8.0×10 -9 mol·L -1 to 1.0×10 -5 mol·L -1 . The detection limit is 1.8×10 -9 mol·L -1 . A simple, rapid and highly sensitive fluorimetric method is proposed for the determination of hymecromone. The results obtained are in agreement with those given by an official method.

Resolution of Spiro[4.4]nonane-1,6-dione by Chiral Inclusion Complexation

The racemic spiro[4.4]nonane-1,6-dione was efficiently resolved through an enantioselective inclusion complexation using chiral host BINOL by simple recrystallization with 31 .9～38.4% yield and 1000%ee.

INCLUSION COMPLEX FORMATION BETWEENα-CYCLODEXTRIN AND BIODEGRADABLE COMBLIKE COPOLYMERS WITH POLY(α,β-MALIC ACID) BACKBONES AND mPEG SIDE CHAINS

Inclusion complexes(ICs) composed ofα-cyclodextrins(α-CD) and biodegradable comblike copolymers with poly(α,β-malic acid)(PMA) backbones and methylated poly(ethylene glycol)(mPEG) side chains were prepared by the host-guest reaction.Two series of ICs with mPEG750 and mPEG2000 were prepared.The stoichiometry(EG/CD) of all the ICs in mPEG2000 series was 3.1,no matter what the graft degree was.While in mPEG750 series,the stoichiometry(EG/CD) was very different:it increased with the amount of mPEG decreasing.Th...

Research of Inclusion Complexation of 4,4'-Thiodiphenol Effected by β-Cyclodextrin in Aqueous Solutions and the Effect on Photodegradation

The inclusion behavior of 4, 4＇ -Thiodiphenol （TDP）, a typical bisphenol and endocrine disruptor, reacts with β-cyclodextrin （β-CD） in aqueous solutions has been investigated by means of UV absorption spectrum and quantum-chemical calculation with Gaussian 98 software. The results show that the inclusion behavior of TDP is quite different in acidic solutions （pH 5.9） from that in alkaline solutions （pH 10.0）. This behavior difference is attributed to the different formula structures in aqueous solutions at acidic and alkaline pH values that are demonstrated by quantum- chemical modeling and calculation. TDP forms a 1 ： 1 fl-CD inclusion complex in aqueous solutions. The equiiibrium constant K was calculated to be 553.49 L/mol at pH 5.9 and 1 318.20 L/mol at pH 10.0 respectively for the inclusion complex reaction by using the modified Benesi-Heldbrand equation. After inclusion TDP＇s structure is changed especially at the inclusion part with the bond order becoming larger, which results in inhibitive photodegradation during direct photooxidation and H2O2 assisted photooxidation.